Under the late Republic Legio XIII was levied by
Julius Caesar in 57 BC, before marching against the
Belgae, in one of his early interventions in intra-Gallic conflicts. During the
Gallic Wars (58–51 BC), Legio XIII was present at the
Battle against the Nervians, the
Siege of Gergovia, and while not specifically mentioned in the sources, it is reasonable to assume that Legio XIII was also present for the
Battle of Alesia. After the end of the Gallic wars, the
Roman Senate refused Caesar his second consulship, ordered him to give up his commands, and demanded he return to
Rome to face prosecution. Forced to choose either the end of his political career or civil war, Caesar brought Legio XIII across the
Rubicon river and into Italy. The legion remained faithful to Caesar during the resulting civil war between Caesar and the conservative
Optimates faction of the senate, whose legions were commanded by
Pompey. Legio XIII was active throughout the entire war, fighting at
Dyrrhachium (48 BC) and
Pharsalus (48 BC). After the decisive victory over Pompey at Pharsalus, the legion was to be disbanded, and the
legionaries "pensioned off" with the traditional land grants; however, the legion was recalled for the
Battle of Thapsus (46 BC) and the final
Battle of Munda (45 BC). After Munda, Caesar disbanded the legion, retired his veterans, and gave them farmland in their native Italy.
Under the Empire Augustus reconstituted the legion once again in 41 BC to deal with the rebellion of
Sextus Pompeius (son of
Pompey) in
Sicily. Legio XIII acquired the
cognomen Gemina ("twin", a common appellation for legions constituted from portions of others) after being reinforced with veteran
legionaries from other legions following the war against
Mark Antony and the
Battle of Actium. Augustus then sent the legion to Burnum (modern
Knin), in
Illyricum, a
Roman province in the Adriatic Sea. In 16 BC, the legion was transferred to
Emona (now
Ljubljana) in
Pannonia, where it dealt with local rebellions. After the disaster of the
Battle of the Teutoburg Forest in AD 9, the legion was sent as reinforcements to Augusta Vindelicorum (
Augsburg), and then to
Vindonissa,
Raetia, to prevent further attacks from the Germanic tribes. Emperor
Claudius sent them back to Pannonia around 45 and the legion built its
legionary fortress at
Poetovium (modern Ptuj, Slovenia). In the
year of the four emperors (69), XIII
Gemina supported first
Otho and then
Vespasian against
Vitellius, fighting in the two
Battles of Bedriacum. After their defeat in the first battle, the victorious Vitellius
forced the legion to build an
amphitheatre in the city of
Bononia. , Romania Under
Trajan the legion took part in both
Dacian wars (101–102, 105–106), and it was transferred by Trajan in 106 to the
newly conquered province of Dacia (in
Apulum, modern
Alba Iulia,
Romania) to garrison it.
Vexillationes of the XIII
Gemina fought under Emperor
Gallienus in northern Italy. The emperor issued a legionary
antoninianus celebrating the legion, and showing the legion's lion (259–260). Another
vexillatio was present in the army of the emperor of the
Gallic Empire Victorinus: this emperor, in fact, issued a gold coin celebrating the legion and its emblem. In 271, the legion was relocated when the Dacia province was evacuated, and restationed in
Dacia Aureliana. In the 5th century, according to the
Notitia Dignitatum, a
legio tertiadecima gemina was in
Babylon in Egypt, a strategic fortress on the Nile at the traditional border between
Lower Egypt and
Middle Egypt, under the command of the
Comes limitis Aegypti. == Attested members ==